The research proposed is an expansion of previous work funded under NIH grant HD-06669. It will relate cognitive ability, previously measured on 1,816 families in the Hawaii Family Study of Cognition, to visual acuity which will be measured by a semi-automated subjective optometer on a subset of about 1,000 families from the original study. The objectives of the research are to determine whether there is a recessive gene for myopia and whether this contributes to cognitive ability as suggested by Karlsson (1975). The mode of inheritance will be explored by mixed-model segregation analysis, and by linkage studies with genetic markers previously determined during the Hawaii Family Study of Cognition. Relationships between visual acuity and fifteen tests of cognitive ability, with four derived factor scores, will be sought by correlation analysis and other appropriate statistical tests.